Angled Screw Channel-Retained vs. Cement-Retained Implant Crowns in Nonmolar Sites: A Systematic Review and Meta-Analysis.

Abstract

Objectives: To evaluate the clinical, radiographic, and aesthetic outcomes of angled screw channel (ASC) retained implant crowns to cement-retained implant crowns in nonmolar sites.

Methods: Randomized and nonrandomized trials comparing ASC-retained and cement-retained implant crowns in single nonmolar locations were found by searching electronic databases (COCHRANE, EMBASE, and MEDLINE) up to January 2025. Changes in marginal bone level were the primary outcomes, whereas periodontal parameters, aesthetic outcomes, and technical complications were the secondary outcomes. Random-effects meta-analysis was used to calculate pooled effect sizes.

Results: A total of 973 studies were identified, of which four studies with 167 single nonmolar implant crowns were included. Overall meta-analysis showed that the difference in marginal bone level was in favor of the ASC group, but the difference was not statistically significant (MD -0.03; 95% CI -0.12 to 0.06; p = 0.57). The ASC group had more positive changes in pink aesthetic score than the cemented group; however, the difference between the two groups was not statistically significant (MD -0.18; 95% CI -0.88 to 0.51; p = 0.61).

Conclusions: ASC-retained implant crowns in nonmolar sites have comparable short-term clinical, radiographic, and aesthetic outcomes to cement-retained implant crowns, with less bleeding on probing expected with ASC-retained crowns.

Clinical significance: The superiority of ASC-retained implant crowns over cement-retained implant crowns in nonmolars was not proven. There were no significant differences between ASC-retained and cement-retained implant crowns in terms of mean changes in marginal bone levels, probing pocket depths, aesthetic outcomes, technical complications, and implant failure.